simplified version of `gc' tag method (only for userdata now).

author: Roberto Ierusalimschy <roberto@inf.puc-rio.br> 1999-10-04 15:51:04 -0200
committer: Roberto Ierusalimschy <roberto@inf.puc-rio.br> 1999-10-04 15:51:04 -0200
commit: 4343420d4d559a7d4cdacdbc1fd61552dcf59f04 (patch)
tree: 57e0bdd41e2f3a4ab70d3150022569751e3d02ad /lstring.c
parent: 1f7103e05d01a6a4c300a73bcfc8d9b17b2c20a4 (diff)
download: lua-4343420d4d559a7d4cdacdbc1fd61552dcf59f04.tar.gz
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1 files changed, 31 insertions, 111 deletions
diff --git a/lstring.c b/lstring.c
index 13a123e3..633fbcd4 100644
--- a/lstring.c
+++ b/lstring.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lstring.c,v 1.20 1999/08/16 20:52:00 roberto Exp roberto $
+** $Id: lstring.c,v 1.21 1999/09/28 12:27:06 roberto Exp roberto $
 ** String table (keeps all strings handled by Lua)
 ** See Copyright Notice in lua.h
 */
@@ -14,17 +14,13 @@
 #include "lua.h"
-#define NUM_HASHSTR     31
-#define NUM_HASHUDATA   31
-#define NUM_HASHS  (NUM_HASHSTR+NUM_HASHUDATA)
 #define gcsizestring(l) (1+(l/64))  /* "weight" for a string with length 'l' */
-static TaggedString EMPTY = {{NULL, 2}, 0L, 0,
+TaggedString luaS_EMPTY = {NULL, MAX_INT, 0L, 0,
-                            {{{LUA_T_NIL, {NULL}}, 0L}}, {0}};
+                           {{{LUA_T_NIL, {NULL}}, 0L}}, {0}};
@@ -49,6 +45,16 @@ void luaS_init (void) {
 }
+void luaS_freeall (void) {
+  int i;
+  for (i=0; i<NUM_HASHS; i++) {
+    if (L->string_root[i].hash != init_hash)
+      luaM_free(L->string_root[i].hash);
+  }
+  luaM_free(L->string_root);
+}
 static unsigned long hash_s (const char *s, long l) {
  unsigned long h = 0;  /* seed */
  while (l--)
@@ -57,12 +63,12 @@ static unsigned long hash_s (const char *s, long l) {
 }
-static int newsize (stringtable *tb) {
+static int newsize (const stringtable *tb) {
  int realuse = 0;
  int i;
  /* count how many entries are really in use */
  for (i=0; i<tb->size; i++) {
-    if (tb->hash[i] != NULL && tb->hash[i] != &EMPTY)
+    if (tb->hash[i] != NULL && tb->hash[i] != &luaS_EMPTY)
      realuse++;
  }
  return luaO_redimension(realuse*2);
@@ -78,7 +84,7 @@ static void grow (stringtable *tb) {
  /* rehash */
  tb->nuse = 0;
  for (i=0; i<tb->size; i++) {
-    if (tb->hash[i] != NULL && tb->hash[i] != &EMPTY) {
+    if (tb->hash[i] != NULL && tb->hash[i] != &luaS_EMPTY) {
      unsigned long h = tb->hash[i]->hash;
      int h1 = h%ns;
      while (newhash[h1]) {
@@ -103,8 +109,8 @@ static TaggedString *newone_s (const char *str, long l, unsigned long h) {
  ts->u.s.len = l;
  ts->constindex = 0;
  L->nblocks += gcsizestring(l);
-  ts->head.marked = 0;
+  ts->marked = 0;
-  ts->head.next = (GCnode *)ts;  /* signal it is in no list */
+  ts->next = ts;  /* signal it is in no list */
  ts->hash = h;
  return ts;
 }
@@ -115,8 +121,8 @@ static TaggedString *newone_u (void *buff, int tag, unsigned long h) {
  ts->u.d.tag = (tag == LUA_ANYTAG) ? 0 : tag;
  ts->constindex = -1;  /* tag -> this is a userdata */
  L->nblocks++;
-  ts->head.marked = 0;
+  ts->marked = 0;
-  ts->head.next = (GCnode *)ts;  /* signal it is in no list */
+  ts->next = ts;  /* signal it is in no list */
  ts->hash = h;
  return ts;
 }
@@ -144,7 +150,7 @@ static TaggedString *insert_s (const char *str, long l, stringtable *tb) {
  int j = -1;  /* last empty place found (or -1) */
  int h1 = h%size;
  while ((ts = tb->hash[h1]) != NULL) {
-    if (ts == &EMPTY)
+    if (ts == &luaS_EMPTY)
      j = h1;
    else if (ts->u.s.len == l && (memcmp(str, ts->str, l) == 0))
      return ts;
@@ -168,7 +174,7 @@ static TaggedString *insert_u (void *buff, int tag, stringtable *tb) {
  int j = -1;
  int h1 = h%size;
  while ((ts = tb->hash[h1]) != NULL) {
-    if (ts == &EMPTY)
+    if (ts == &luaS_EMPTY)
      j = h1;
    else if ((tag == ts->u.d.tag || tag == LUA_ANYTAG) && buff == ts->u.d.v)
      return ts;
@@ -200,115 +206,29 @@ TaggedString *luaS_new (const char *str) {
 TaggedString *luaS_newfixedstring (const char *str) {
  TaggedString *ts = luaS_new(str);
-  if (ts->head.marked == 0)
+  if (ts->marked == 0) ts->marked = 2;  /* avoid GC */
-    ts->head.marked = 2;  /* avoid GC */
  return ts;
 }
-void luaS_free (TaggedString *l) {
+void luaS_free (TaggedString *t) {
-  while (l) {
+  L->nblocks -= (t->constindex == -1) ? 1 : gcsizestring(t->u.s.len);
-    TaggedString *next = (TaggedString *)l->head.next;
+  luaM_free(t);
-    L->nblocks -= (l->constindex == -1) ? 1 : gcsizestring(l->u.s.len);
-    luaM_free(l);
-    l = next;
-  }
-}
-/*
-** Garbage collection functions.
-*/
-static void remove_from_list (GCnode *l) {
-  while (l) {
-    GCnode *next = l->next;
-    while (next && !next->marked)
-      next = l->next = next->next;
-    l = next;
-  }
-}
-TaggedString *luaS_collector (void) {
-  TaggedString *frees = NULL;
-  int i;
-  remove_from_list(&(L->rootglobal));
-  for (i=0; i<NUM_HASHS; i++) {
-    stringtable *tb = &L->string_root[i];
-    int j;
-    for (j=0; j<tb->size; j++) {
-      TaggedString *t = tb->hash[j];
-      if (t == NULL) continue;
-      if (t->head.marked == 1)
-        t->head.marked = 0;
-      else if (!t->head.marked) {
-        t->head.next = (GCnode *)frees;
-        frees = t;
-        tb->hash[j] = &EMPTY;
-      }
-    }
-  }
-  return frees;
-}
-TaggedString *luaS_collectudata (void) {
-  TaggedString *frees = NULL;
-  int i;
-  L->rootglobal.next = NULL;  /* empty list of globals */
-  for (i=NUM_HASHSTR; i<NUM_HASHS; i++) {
-    stringtable *tb = &L->string_root[i];
-    int j;
-    for (j=0; j<tb->size; j++) {
-      TaggedString *t = tb->hash[j];
-      if (t == NULL || t == &EMPTY)
-        continue;
-      LUA_ASSERT(t->constindex == -1, "must be userdata");
-      t->head.next = (GCnode *)frees;
-      frees = t;
-      tb->hash[j] = &EMPTY;
-    }
-  }
-  return frees;
-}
-void luaS_freeall (void) {
-  int i;
-  for (i=0; i<NUM_HASHS; i++) {
-    stringtable *tb = &L->string_root[i];
-    int j;
-    for (j=0; j<tb->size; j++) {
-      TaggedString *t = tb->hash[j];
-      if (t != &EMPTY) luaM_free(t);
-    }
-    if (tb->hash != init_hash) luaM_free(tb->hash);
-  }
-  luaM_free(L->string_root);
 }
-void luaS_rawsetglobal (TaggedString *ts, TObject *newval) {
+void luaS_rawsetglobal (TaggedString *ts, const TObject *newval) {
  ts->u.s.globalval = *newval;
-  if (ts->head.next == (GCnode *)ts) {  /* is not in list? */
+  if (ts->next == ts) {  /* is not in list? */
-    ts->head.next = L->rootglobal.next;
+    ts->next = L->rootglobal;
-    L->rootglobal.next = (GCnode *)ts;
+    L->rootglobal = ts;
  }
 }
-const char *luaS_travsymbol (int (*fn)(TObject *)) {
-  TaggedString *g;
-  for (g=(TaggedString *)L->rootglobal.next; g; g=(TaggedString *)g->head.next)
-    if (fn(&g->u.s.globalval))
-      return g->str;
-  return NULL;
-}
 int luaS_globaldefined (const char *name) {
  TaggedString *ts = luaS_new(name);
  return ts->u.s.globalval.ttype != LUA_T_NIL;
 }
author	Roberto Ierusalimschy <roberto@inf.puc-rio.br>	1999-10-04 15:51:04 -0200
committer	Roberto Ierusalimschy <roberto@inf.puc-rio.br>	1999-10-04 15:51:04 -0200
commit	4343420d4d559a7d4cdacdbc1fd61552dcf59f04 (patch)
tree	57e0bdd41e2f3a4ab70d3150022569751e3d02ad /lstring.c
parent	1f7103e05d01a6a4c300a73bcfc8d9b17b2c20a4 (diff)
download	lua-4343420d4d559a7d4cdacdbc1fd61552dcf59f04.tar.gz lua-4343420d4d559a7d4cdacdbc1fd61552dcf59f04.tar.bz2 lua-4343420d4d559a7d4cdacdbc1fd61552dcf59f04.zip